Officials of the D.C. school board and teachers union announced yesterday that they had resolved a procedural snag in their long-stalled contract negotiations and will begin substantive talks late next week.

The union is still calling for a "work to the rule" job action, teachers union president William H. Simons said. But the job action - involving refusal to perform school duties after hours or to take paperwork home - will last only until Sept. 22, when negotiations are scheduled to resume, Simons said.

The issue that had been holding up negotiations since last spring concerned the number of hours teachers on the negotiating committee could be away from their classrooms without losing pay.

The Board of Education had proposed a limit of 480 hours, or 80 hours for each of the six members of the negotiating committee. The union had argued that negotiating time should be unlimited, as in the past. But at the joint press conference yesterday afternoon outside Marie Reed Elementary School at 18th Street and Wyoming Avenue NW, Simons and board president Conrad Smith announced that the negotiating hours would be settled, retroactively, at the bargaining table.

If teachers wind up spending more time at talks than the ceiling eventually agreed on, the union will pay the difference in salary, Simons explained.

The teachers contract expired in January but was extended through July when negotiations first stalled.

Smith and Simons both praised mayoral candidate Marion Barry for resolving the snag during formal and informal conversations the last several weeks. Both men have endorsed Barry, and some of the conversations they referred to were said to have taken place at Barry campaign affairs.

"It seems easy but it wasn't easy to get them together, believe me," said Barry as he stood alongside Smith and Simons at yesterday's sidewalk news conference.